AlterWAN, Inc. appealed a stipulated final judgment of noninfringement in the District of Delaware, No. 1:19-cv-01544, favoring Amazon.com, Inc. and Amazon Web Services, Inc. The Federal Circuit decided the appeal on September 11, 2026. Judge Prost wrote for the majority with Judge Lourie; District Judge Subramanian (S.D.N.Y., sitting by designation) dissented.
What the court held
The majority affirmed the district court's constructions of "cooperating service provider" and "non-blocking bandwidth" in claims 18 and 51 of U.S. Patent 8,595,478, titled in public records as "Wide area network with high quality of service." Because those constructions supported the stipulated noninfringement judgment, the majority did not reach the exclusion of AlterWAN's damages expert.
The district court construed "cooperating service provider" as a service provider that agrees to provide non-blocking bandwidth. The dissent argued that construction is wrong and would make other claim language about insufficient bandwidth meaningless.
What it means
The majority tied "cooperating service provider" to an agreement to provide non-blocking bandwidth. The affirmed construction qualified that bandwidth requirement: it must be available while the network is able to transmit data. The dissent argued that requiring non-blocking bandwidth conflicts with claim language addressing insufficient bandwidth and pruning paths.
What to watch next
Watch for any rehearing request and for how later cloud and SD-WAN cases treat "non-blocking" style QoS language. Also watch whether AlterWAN continues other enforcement on the '478 patent family outside Amazon.